LED Grow Light Forum

I'd skip the intake fan and leave it passive. If you have a 400+ CFM fan at the top of the cab it should be fine as long as you're sucking the hot air out and not blowing attic air in by mistake...

I'll unplug the intake fan and let it run for a while and see how that does, I'll have to do trial an error.

What is the hottest my cab should be?

You want to shoot for 78F - 80F, measured at the canopy, but if it spikes a little for short periods it should be ok.

Search for "The Famous Overgrow Marijuana Cannabis Growing FAQ 800+ Grow FAQ Basic Topics" and you'll find a lot of your questions answered there...

The booster fan is blowing air into the cabinet...

With out my 120 CFM blowing air into the cabinet my temps rise...

Here is a breakdown on temps
1:45pm 75 degrees with lights off.

5:15 pm 81.5 lights on (lights on at 5pm) bedroom temp 75 with RH 42%

6PM 82.5 lights on bedroom temp 78 with 43% RH

7:50 pm 82.4 lights on with 77 room temp 43% RH

11:30 pm 82.5 cab with 78 room temp with 45% RH

I don't agree with the 80s being my temp... Something must be able to be done...

I have a 402 CFM fan.... With 2 fans blowing air around the cab with the light off, I have no heat issues.

When the light is on I'm at 84-86 temps when the booster fan is on at the top blowing air into the cab it shows temps around 82.5-80 degrees...

The company claims with proper exhaust and intakes I shouldn't have heat issues but I have 3 intakes and 1 CFM sucking out 11x the amount of air, how do I have heat issues?

I don't know why; with the 400+CFM exhaust and a large enough intake the temps shouldn't be that high, even with a bigger light. Try lowering the temp of the room by 3 degrees and see if that helps.

What are the dimensions of your cab?

Product Specifications
Dimensions 36 × 24 × 72 in

With a 400w air cooled tube had no heat issues... With my 2 UFO I had no heat issues...

I agree, you shouldn't be having those heat issues because the SS400w puts out about the same amount of heat as the 400w HPS cool tube maybe even a bit less.

Do you have an IR thermometer? Check the temps of the intake air and the exhaust air. Check the temps at the bottom, middle and top of the cab. Check the temps 18-24" below the light.

I'm starting to think that you might be getting a bad reading due to the placement of your thermometer, is it fixed in one place or can it be moved? I think the exhaust fans built into the SS400w might be blowing towards the thermometer so it's measuring the exhaust temp of the light, not the room. You can try turning the light 90 degrees too...

temps on the leafs show 77

temps of air coming out of the light show 87-88

temps at the top of cab show 84.6

I may end up using my 2x4x7 tent and take it out of the cab...

That all seems pretty normal:
77 at the canopy is great.
84 at the top is fine because you don't grow there and heat rises.

Try rotating the light 90 degrees or moving the thermometer if it's not fixed...